Arc suppressor

ABSTRACT

An arc chute or arc suppressor including a supporting casing in covering relationship with a pair of stationary contact jaws cooperable with an electrical switch blade, cold-molded arcsuppressive material supported in the casing forwardly of the contact jaws, and a plurality of generally U-shaped metal plates supported in spaced relationship forwardly of the contact jaws by the arc-suppressive material, the plate nearest the contact jaws being substantially completely covered on the surface thereof facing the contact jaws by the arc-suppressive material.

United States Patent [72] inventor Tadeusz J. Rys Lexington, Ky. [21]Appl. No 823,396 (22] Filed May 9, 1969 [45] Patented July 27, 1971 [73]Assignee Square D Company Park Ridge, 111.

[54] ARC SUPPRESSOR 4 Claims, 6 Drawing Figs.

(52] US. Cl

[51 1 Int. Cl .0 [50] Field of Search [56] References Cited UNITEDSTATES PATENTS 2,467,937 4/1949 Jackson 2,524,287 10/1950 Ellis ,7 h200/147 2,836,683 5/1958 Souchet 200/144 3,441,699 4/1969 Erickson a t t200/144 Primary Examiner-Robert S. Macon Attorneysl-larold J. Rathbunand Paul J. Rose ABSTRACT: An arc chute or are suppressor including asupporting casing in covering relationship with a pair of stationarycontact jaws cooperable with an electrical switch blade, coldmoldedarc-suppressive material supported in the casing forwardly of thecontact jaws, and a plurality of generally U- shaped metal platessupported in spaced relationship forwardly of the contact jaws by thearc-suppressive material, the plate nearest the contact jaws beingsubstantially completely covered on the surface thereof facing thecontact jaws by the 200/ 147 arc-suppressive material.

5/ O :i 5g

PATENTEDJULNIQH 3.596 026 SHEET 1 UF 2 FIG. I +4 ENTOR.

ARC SUPPRESSOR This invention relates generally to are chutes or aresuppressors for multipole electric safety switches, and moreparticularly to an arc suppressor including cold-molded arc-suppressivematerial which supports a plurality of metal plates in spacedrelationship and also completely covers the surface of the plate nearestthe origin of the are on the side thereof facing the arc origin.

In the drawings, FIG. 1 is a front elevational view of one pole portionof a multipole fusible safety switch including an arc suppressorconstructed in accordance with this invention;

FIG. 2 is a sectional view taken along the line 22 of FIG. 1;

FIG. 3 is a sectional view taken along the line 3--3 of FIG. 1;

FIG. 4 is a fragmentary sectional view taken generally along the line4-4 ofFIG. 1;

FIG. 5 is a fragmentary sectional view of the structure of FIG. 1 takenalong the line 5-5 of FIG. 4; and

FIG. 6 is a sectional view taken along the line 6-6 of FIG. 3.

The drawings illustrate a single pole portion of a multipole fusiblesafety switch similar to that disclosed in US. Pat. No. 3,339,047,issued Aug. 29, I967. A base 10 molded ofinsulating material issecurable to the rear wall of an enclosure (not shown). Secured to thebase 10 by a pair of screws 12, only one of which is shown in FIG. 4, isa terminal strap 14 which includes a rear platform 14a and a frontplatform 14b joined by a connecting portion 140 (FIG. 3).

A relatively large connector including a stepped body 16 (FIGS. 1 and 3)having a pair of clamping screws 18 threadedly mounted therein issecured to the front platform 14b by a bolt 19 and a nut 20. Further, arelatively small connector including a stepped body 22 having a clampingscrew 24 threadedly mounted therein is secured to the platform 14b by abolt 25 and a nut 26. The two connectors are provided because a singlewire cable large enough to carry the current for which the switch isdesigned would be too stiff and unwieldy. The bolts 19 and 25 are heldcaptive in the platform 14b by a pin 28 disposed in the connectingportion 14c, the heads of the bolts being disposed between the pin 28and the platform 14b. Further, the bolts 19 and 25 are disposed onopposite sides of the connecting portion 14c and a flat surface on thehead of each bolt abuts an adjacent surface of the connecting portion140 to prevent rotation of the bolts.

A stationary contact assembly including a double jaw member 30 (FIGS. 3and 4) and a contact pressure spring member 32 is secured to the rearplatform 1411 by a bolt 33 and a nut 34, the head of the bolt 33 beingrecessed within the base 10. A hoodlike casing 36 molded of insulatingmaterial is secured on one side to the rear platform 14a by a screw 37(FIG. 3) and on the other side to the base 10 by a pair of screws 38(FIGS. 1 and 3).

Secured within the casing 36 are a pair of complementary support members40 and 41 formed of cold-mold, arc-suppressive insulating material suchas melamine bonded oxides or hydrates of aluminum or magnesium. A pairof screws 42 and 43 and cooperating nuts 44 and 45 secure the supportmembers 40 and 41 respectively to opposite sidewalls of the casing 36.In addition, the casing 36 is provided with a pair of projections 36aand 36b (FIGS. 5 and 6) which extend into appropriate recessesrespectively in the support members 40 and 41. Adjacent the front end,the upper wall of the casing 36 is provided with a series of vent holes360. A plurality of generally U-shaped metal plates 48 are mounted inspaced relationship in complementary grooves provided in the supportmembers 40 and 41.

Also secured to the base 10 by a pair of screws 50 (FIG. 4) is acombination fuse and switch blade mounting means including a pair ofaligned generally U-shaped spring members 52 (FIGS. 1 and 2), agenerally U-shaped mounting member 54 disposed within the spring members52, a generally L- shaped mounting member 56 disposed within themounting member 54, and an anchoring plate 58 into which the screws 50are threaded to secure the members 52, 54, and 56 to the base 10. A pin60 is mounted adjacent one end in the member 56 and adjacent the otherend in one leg portion of the member 54. A switch blade 62, movable byblade actuating means not shown, is pivotally mounted on the pin 60. Theend portion of the pin 60 mounted in the one leg portion of the member54 is larger in diameter than the remainder thereof and is trappedbetween the switch blade 62 and one leg portion of one of the springmembers 52 to prevent axial movement of the pin. A spacer 64 is mountedbetween the member 56 and the one leg portion of the member 54 adjacentthe other end of these members from the pin 60. The space 64 may have asmaller diameter portion (not shown) projecting into either the member56 or the member 54. Before being secured to the base 10 by the screws50, the assembly including the members 52, member 54, member 56,anchoring plate 58, pin 60, switch blade 62, and spacer 64 is securedtogether by a pair of screws 66 also threaded into the anchoring plate58.

Another base 68 (FIG. 1) molded of insulating material is securable tothe rear wall of the enclosure (not shown) in spaced relationship to thebase 10. Secured to the base 68 is a terminal strap 70 similar to theterminal strap 14 and having connector bodies identical to bodies 16 and22 secured to the front platform thereof. A fuse clip 72 reinforced by aspring member 74 is secured to the rear platform of the terminal strap70. A fuse 76 having blade terminals adjacent opposite ends is shownwith one blade terminal mounted in the fuse clip 72 and the other bladeterminal mounted between the member 56 and the other leg portion of themember 54.

As shown in FIGS. 3 and 4, the support members 40 and 41 respectivelyinclude portions 400 and 41a disposed above the jaw member 30 andextending rearwardly of the front end thereof, where any are wouldoriginate upon separation of the switch blade 62 from the jaw member 30.

Further, as shown in FIGS. 4 and 6, the support members respectivelyinclude portions 40b and 41b which together substantially completelycover the plate 48 nearest the jaw member 30 on the side of the platefacing the jaw member. In addition, as shown in FIGS. 4 and 5, thesupport members respectively include portions 400 and 41c which supportthe plates 48 in spaced relationship and respectively line oppositewalls of the casing 36. The construction and arrangement result in anarc suppressor which can repeatedly withstand interruption of largercurrents than formerly possible with an arc suppressor of similar size.

Iclaim:

1. In a switch having a stationary contact jaw member cooperable with apivotable switch blade, an arc suppressor comprising a hoodlike casingsecured in covering relationship to the jaw member and having an openside facing the switch blade, a pair of complementary cold-moldedarc-suppressive insulating support members secured respectively to apair of opposed side walls of the casing, and a plurality of generallyU-shaped, flat, metal plates held by the support members in spaced-apartrelationship forwardly of the jaw member, each of the support membershaving a covering portion covering substantially one-half of the metalplate nearest the jaw member on the side thereoffacing the jaw member.

2. An arc suppressor as claimed in claim 1 wherein each of the supportmembers lines one of the pair of opposed sidewalls of the casing at theend thereof opposite the jaw member.

3. An arc suppressor as claimed in claim 1 wherein each of the supportmembers has a portion extending from an upper end of the coveringportion which covers half the metal plate nearest the jaw member, lininga portion of an upper wall of the casing opposite the open side, andextending rearwardly of the front end of the jaw member.

4. An arc suppressor as claimed in claim 1 wherein each of the supportmembers has a portion extending in a direction away from the jaw memberfrom a lower end portion which covers half the metal plate nearest thejaw member, and covering the lower edge portions of one leg portion ofeach of the generally U-shaped metal plates.

I mg?" UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.315965026 Dated u ly 27 197].

Inventor(s) Tadeusz J. Rys

It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

CojLumn 2, line 72, after "portion" insert "oi the covering port1ou-Signed and sealed this 11th day of January 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting, Officer- ActingCommissioner of Patents

1. In a switch having a stationary contact jaw member cooperable with apivotable swItch blade, an arc suppressor comprising a hoodlike casingsecured in covering relationship to the jaw member and having an openside facing the switch blade, a pair of complementary cold-moldedarc-suppressive insulating support members secured respectively to apair of opposed side walls of the casing, and a plurality of generallyU-shaped, flat, metal plates held by the support members in spaced-apartrelationship forwardly of the jaw member, each of the support membershaving a covering portion covering substantially one-half of the metalplate nearest the jaw member on the side thereof facing the jaw member.2. An arc suppressor as claimed in claim 1 wherein each of the supportmembers lines one of the pair of opposed sidewalls of the casing at theend thereof opposite the jaw member.
 3. An arc suppressor as claimed inclaim 1 wherein each of the support members has a portion extending froman upper end of the covering portion which covers half the metal platenearest the jaw member, lining a portion of an upper wall of the casingopposite the open side, and extending rearwardly of the front end of thejaw member.
 4. An arc suppressor as claimed in claim 1 wherein each ofthe support members has a portion extending in a direction away from thejaw member from a lower end portion which covers half the metal platenearest the jaw member, and covering the lower edge portions of one legportion of each of the generally U-shaped metal plates.